We are in an odd environment, where only individual users who are in a computer class need to have access to Firefox itself, and Firefox needs to have access to local files that are saved web pages which are also restricted to those students. This is a prison where the security staff only want a subset of students to have access to Firefox. Context: a locked-down Windows 7 Pro notebook, running disconnected from a network. The specific version of Firefox we are using is the last Firefox 52 developer version (Windows x64) prior to update to 53. We have not tested with other versions, but we have seen similar problems on earlier versions of Firefox Developer Version 52. In Windows local security, we would like to have the program directory for Firefox, and the directory containing .html files (for example, saved websites for offline viewing) be controlled by adding students who are in a computer class to a local use user group, let's call if FirefoxUsers. Then we remove the default group Authenticated Users from access, so that only users in a FirefoxUsers can access Firefox. What happens is that Firefox fails to fully load when you start it using a user account of one of the students in FirefoxUsers who should have access. The start screen never fully appears, and if you press for example the button to show the developer toolbox, you get a beachball and the developer toolbox never appears. There is a workaround: add the individual user to the folder from which the Firefox program folder inherits its permissions, rather than a user group containing the user. Similarly, if we apply that workaround for the Program Files folder so that Firefox can start, but try to access files from Firefox (Files/Open File ...) protected with FirefoxUsers, then a similar problem appears. That is, the file fails to open, and Firefox displays a screen showing an Access error. We have many other programs using the same security system that do not show this issue.
You need to log in before you can comment on or make changes to this bug.